- Remove obsolete documentation files
- Removed old obsolete information from some documentation files

Added to new values to the server variable use_stat_tables.
The values are COMPLEMENTARY_FOR_QUERIES and PREFERABLY_FOR_QUERIES.
Both these values don't allow to collect EITS for queries like
    analyze table t1;
To collect EITS we would need to use the syntax with persistent like
   analyze table t1 persistent for columns (col1,col2...) index (idx1, idx2...) / ALL

Changing the default value from NEVER to PREFERABLY_FOR_QUERIES.

use_stat_tables= PREFERABLY
optimizer_use_condition_selectivity= 4

MDEV-17928 Conversion from TIMESTAMP to VARCHAR SP variables does not work well on fractional digits

Sort acl_users inside the mysql_rename_user()'s loop, after every
successful iteration.

This is needed because on the next loop's iteration find_user_exact()
is used, which requires correct sorting by name.

&sys_buf + DATA_TRX_ID_LEN is not &(sys_buf + DATA_TRX_ID_LEN).

create_table_def(), ha_innobase::create(): Defer fts_optimize_add_table()
until after the table has been successfully created.

row_fts_merge_insert(): Correctly initialize DB_ROLL_PTR to a safe value
that will not be dereferenced by MVCC.

This patch changes how old rows in mysql.gtid_slave_pos* tables are deleted.
Instead of doing it as part of every replicated transaction in
record_gtid(), it is done periodically (every @@gtid_cleanup_batch_size
transaction) in the slave background thread.

This removes the deletion step from the replication process in SQL or worker
threads, which could speed up replication with many small transactions. It
also decreases contention on the global mutex LOCK_slave_state. And it
simplifies the logic, eg. when a replicated transaction fails after having
deleted old rows.

With this patch, the deletion of old GTID rows happens asynchroneously and
slightly non-deterministic. Thus the number of old rows in
mysql.gtid_slave_pos can temporarily exceed @@gtid_cleanup_batch_size. But
all old rows will be deleted eventually after sufficiently many new GTIDs
have been replicated.

only --datadir option is tested in this test.
Other options (notably --password and --service) would need another,
more comprehensive test.

merge_role_db_privileges() was remembering pointers into Dynamic_array
acl_dbs, and later was using them, while pushing more elements into the
array. But pushing can cause realloc, and it can invalidate all pointers.

Fix: remember and use indexes of elements, not pointers.

sorting them by usernames first, and then by get_sort() value.


Search functions now use binary search to find the the first entry with
given name. Then, linear search is done, until the first match.

The previous patch 269da4bf was
actually for MDEV-8894 (not for MDEV-5377). It was erroneously
pushed with a wrong title.

This patch is a small cleanup for MDEV-8894.
CREATE TABLE is now not a part of binary logs recorded with MySQL,
only INSERT statements are. This will allow to reuse the same binary
logs in combinations with different CREATE TABLE statements,
to tests different data types.

MDEV-5377 Row-based replication of MariaDB temporal data types with FSP>0 into a different column type